Lathe dog



' Oct. 11. 1927.

s. E. BOYNTQN LATHE nos Filed Oct. 17, 1924 m QW/ 10% K Patented Get. 11, 1927.

UNITED. STATES PATENT OFFICE.

STANLEY E. BOYNTON, OF OAK PARK, ILLINOIS, ASSIGNOR TO CHARLES E. REED.

LATHE DOG.

Application fi1ed October 17, 1924. Serial No. 744,182.

My invention relates, more particularly, to lat-he dogs for use in connection with copying lathes for producing shoe lasts; and my primary object is to provide a construction of lathe dog which may be adjusted on its support into different positions to conform to different shaped heel portions of last-patterns used in such lathes, and by the use of which lathe dogs the stubs remaining on the heel portions of the last-blanks after the latter have been turned into last form, will extend in the same position relative to the upper and lower surfaces of the lasts regardless of variations in the contour of the heel portions of the patterns, such condition being highly desirable in connection with the further operation on the last-blanks to remove the stubs, which operation is commonly performed by machines provided for this purpose.

Referring to the accompanying drawings: V

Figure 1 is a broken face view of the swinging frame portion of a copying'lathe for producing lasts in accordance with a pattern-last and comprising av head-stock spindle for the last-pattern equipped with my improved lathe dog. Figure 2 a broken view in side elevation of the head-stockspindle for the last-pattern blank, viewing the structure in the position shown in Fig. 1, and showing the lathe dog adjusted into differentpositions to conform to last-patterns having heel portions presenting different contours. Figure 3 1s a longitudinal plan section of the lathe dog and its immediate supporting structure; and Figure 4, a plan view of the spindle and dog. -While my invention is applicable generally to lathe structures, I have shown it as embodied, for the purpose of illustration, in a machine of the general construction shown in the pending application of Charles E. Reed for United States Letters Patent, Serial No. 650,194, filed July 7, 1923, but not, however, with the intention of limiting it to use in such a construction.

' As machines of the general construction shown, and above referred to,are commonly known, it. will be suflicienttostate that 5 represents a frame which, in accordance with common practice, is pivotally supported at its upper end on the frame work of themachine to extend dependingly into a pos tion in which itopposes the patternfollower and the lfl$t-cutting mechanism mounted on the the pattern and last-blank. In the arrange-- ment shown the frame 5 is provided with a shaft 12 driven, through gearing (not shown) in a gear-case 13, on this frame, by a shaft 1 1 which, in turn, is driven by mechanism (not shown) on the machine. The shaft 12 is in driving engagement with the shaft 15 of the spindle of the head-stock 8 through the medium of gearing (notshown) in a gear-case 16 on the frame 5, and the spindles 17 of the head-stock 9 is driven from the shaft 12 by gearing (not shown) in a gear-case 12 also provided on this frame;

In further explanation of the construction of the machine shown, it may be stated that as the pattern 6 is rotated against the pattern follower the frame 5 will swing toward and away from the axis of the pattern follower, thereby moving the last-blank 7 toward and away from the axis of the cutting mechanism to produce the proper shape of last. I I I The head-stock 8 for the pattern is equipped with my improved lathe dog, the

preferred construction of which is that disclosed and comprises a sleeve-like body 18 containing a socket .19which fits over, and is keyed to, the shaft15 with whichit cooperates,.the sleeve 18 containing a slot 20, the rear wall of which, represented at 20 is of arc shape, the are of which is described about a point in the longitudinal axis of the shaft 15 and substantially in a line connecting the extremities of that part of the dog which engages the heel portion of the pattern last. Thedevice also comprises a dog proper 21 which extends into. the slot 20, its

rear edge portion, represented at 22, being of arc shape, the radius of the arc of which is the same as the are described bythe wall 20 of the slot 20. The dog 21 contains an arcuate slot 23 through which, and through alining'openings 24: and 25 in the slotted part of the body Vmember 18, a clamping screw '26 extends, the threaded end of this screw screwing into the opening 24%, the latter beingthreaded. The body member 18 is slotted crosswise thereof, as represented at 2'? at the base of .one of the arms thereof and produced by forming the slot 20, to render this part of the member defieotable into 7 clamping engagement with the dog 21 when the screw 26 is tightened, for holding the dog in adjusted position on the member 18. The outer end surface of the dog is provided with teeth 28, curved as shown, to penetrate the end of pattern at its heel portion as shown in Fig. 1. v

By forming the partsof the head-stock 8, as shown and described, the dog 21 maybe tilted into various positions of adjustment on the member 18 to cause its teeth-equipped portion to conform to the heel portions of patterns having different contours at their rear end surface.

The provision of the curved contacting l surfaces 20 and 22 as described which are inmutual contact in the various adjustments of the dog for different forms of heels, compels the dog, in the tilting thereof tow conform to the heel of a pattern-last introduced into the lathe between the head and tail stocks, to movein such a predetermined path that a point midway between the points of tion relatively to the axis of the spindle during the adjustments of the dog, it follows that all points in the last will retain their positions relatively to the axis of the spindle or the axis of rotation of the last, and that no tilting of the last will take place during the adjustments of the dog to the particulancontour of the heel portion of the last introduced into the machine, and

thus the stubs producedjon the last-blanks, the one produced on the last Tbeing represented by dotted linesat 29, are in the same position relative to the upper and lower surfaces of the formed lasts, -with the known advantages. a In this connection it may be stated that while the dog as shown is unprovided with any part, such as a spur,'projecting beyond a line connecting the extremities of its teeth, the dog, withoutdepartmg from the spirit of my invention, may be provided with such a projecting 'part, provided such part does not interfere with thercentering of theadjustment accordingto the curvatureof the heel en'gaging portion of the dog; thus a projecting part of such small size that the wood of the heel into which such part proects would readily give, in making such ad ustment or one of larger proportlons, provided the heel portion of the last is pre liminarily recessed to loosely receive it, may be provided on the dog, if found desirable, without departing from my invention, it being my intention that the recital in the claims appended hereto that the dog is free of any projecting part, which in the application of the last thereto would interfere with the centering of the adjustment according to said curvature about said point be notconstrued to exclude a dog provided with a projection provided such projection'does not interfere with the centering of the adjustment of the dog according to its curvature in the application of a last thereto;

While I'illustrated and described a particular construction embodying my inventional did not wish to be understood as limiting it thereby. as the same may be variously modified and altered without departing from the spiritof the invention.

What I claim as new, and desire to secure by Letters Patent, is: I

1. A spindle for a last-lathe stock for engaging the heel portion of a pattern last comprising a body portion and a. dog portion adjustable thereon, one of said portions having an arc-shaped surface extending generally crosswise of the spindle, the curvature of said surface being in a direction crosswise of the splndle and concentrlc with the extremities of that portion of the dog which engages the heel portion of the pattern last, said dog being free of any projectingpart which, in the application of the 7 last thereto, would interfere with the centering of the adjustment according to said lllt) -a point substantially in a line connecting comprising a body portion, a dog portion I adjustable thereon, one of said portions havmg an arc-shaped surface extending generally crosswise of thespindle, nthe curvature v of said surfacebeing in a direction crosswise of the spindle and concentric with a point substantially in a line connecting the extremities of that, portion of the dog which engages the heel portion of the pattern last, said dogbeing free ofany projecting part which, in the application of the last there to, would interfere with the centering of the ad ustment according to said curvature about said point, the other of said portions engaging with, and. movable along, said surface, andwmeans for securing said dog. to said body portion in adjusted position thereon. Y i

3. A spindle for a last-lathe stock for engaging the heel portion of a pattern last comprising a body portion containing a slot extending lengthwise of the spindle, adog extending into said slot and adjustable therein, said slot and dog having engaging surfaces one of which is arc-shaped and extends generally crosswise of the spindle with its curvature in a direction crosswise of the spindle, said dog containing a slot, and means extending into said slot for securing said dog in adjusted position on said body portion, said slot in said dog being elongated in a direction crosswise of the axis of said spindle to permit movement of said dog on said body portion in the adjusting of said dog, and said curved surface being concentric with a. point substantially in a line connecting the extremities of that portion of the dog which engages the heel portion of the pattern last, said dog being free of any projecting part which, in the application of the last thereto, would interfere with the centering of the adjustment according to said curvature about said point.

at. A spindle for a last-lathe stock for engaging the heel portion of a pattern last comprising a body portion and a dog adjustable thereon, said body portion and dog having mutual contacting arc-shaped surfaces extending generally crosswise of the spindle. the curvature of said surfaces being in a direction crosswise of the spindle andsaid arc-shaped surfaces being concentric with a point substantially in a line connecting the. extremities of that portion of the dog which engages the heel portion of the pattern last, said dog being free of any projecting part which, in the application of the last thereto, would interfere with the centering of the adjustment according to said curvature about said point.

5. A spindle for a last-lathe stock for engaging the heel portion of a pattern last comprising a body portion, a dog adjustable a point substantially in a line connecting the extremities of that portion of the dog which engages the heel portion of the pattern last,

said dog being free of any projecting part which, in the application of the last thereto, would interfere with the centering of the adjustment according to saidcurvature about said point, and means for securing said dog to said body portion in adjusted position thereon.

6. A spindle for a last-lathe stock for en gaging the heel portion of a pattern last comprising a body portioncontaining a slot extending lengthwise of the spindle, the rear wall of said slot being of arc-shape and extending generally crosswise of the spindle with the curvature of said wall being in a direction crosswise of the spindle, a dog extending into said slot and adjustable therein, said dog having a curved surface contacting with said curved rear wall of said slot and containing a slot, and means extending into said slot for securing said dog in adjusted position 011 said body portion, said slot in said dog being elongated in a direction crosswise of the axis of said spindle to permit movement of said dog on said body portion in the adjusting of said dog, and said curved rear wall of the slot in said body portion being concentric with a point substantially in a line connecting the extremities of that portion of the dog which engages the heel portion of the pattern last,

said dog being free of, any projecting part if which, in the application of the-last thereto, would interfere with the centering of the adjustment according to said curvature about said point.

STANLEY E. BOYNTON. 

